Drug

Lasofoxifene

In clinical development

ClassEstrogen receptor modulatorEmerging researchLate-stage development

Also known as (-)-cis-5,6,7,8-Tetrahydro-6-phenyl-5-(p-(2-(1-pyrrolidinyl)ethoxy)phenyl)-2-naphthol.

RxNorm300511 ChEMBLCHEMBL328190 ATCG03XC03UNII337G83N988

Research papers

Active clinical trials

Protein targets

Latest activity

beta

Recent clinical, regulatory, research and industry developments relating to this drug.

I-SPY Trial (Investigation of Serial Studies to Predict Your Therapeutic Response With Imaging And moLecular Analysis 2)

Clinical trial2026-05-06Results expected Q4 2030 · ClinicalTrials.gov

An Open-Label, Randomized, Multicenter Study Evaluating the Activity of Lasofoxifene Relative to Fulvestrant for the Treatment of Pre- and Postmenopausal Women With Locally Advanced or Metastatic ER+/HER2- Breast Cancer With an ESR1 Mutation

Clinical trial2025-05-08Completed · ClinicalTrials.gov

Lasofoxifene versus fulvestrant for ER+/HER2- metastatic breast cancer with an ESR1 mutation: results from the randomized, phase II ELAINE 1 trial.

Research2023-12-01Annals of oncology : official journal of the European Society for Medical Oncology

Open-label, phase II, multicenter study of lasofoxifene plus abemaciclib for treating women with metastatic ER+/HER2- breast cancer and an ESR1 mutation after disease progression on prior therapies: ELAINE 2.

Research2023-12-01Annals of oncology : official journal of the European Society for Medical Oncology

PEARL: Postmenopausal Evaluation And Risk-Reduction With Lasofoxifene

Clinical trial2007-12-01Completed · ClinicalTrials.gov

The Effect Of Lasofoxifene On Local Mediators Of Bone Resorption In The Prevention Of Postmenopausal Osteoporosis

Clinical trial2007-09-01Completed · ClinicalTrials.gov

Dose Response Study Of Lasofoxifene In Postmenopausal Women With Osteoporosis (Placebo-Controlled, Multicenter, Double-Blind, Comparative Study) - Japanese Asian Dose Evaluation: JADE

Clinical trial2006-03-01Completed · ClinicalTrials.gov

Double-Blind Placebo-Controlled Trial Of The Safety, Toleration and Efficacy Of Lasofoxifene 0.25 Mg/D and Raloxifene 60Mg/D For The Prevention Of Bone Loss In Postmenopausal Women

Clinical trial2005-10-01Completed · ClinicalTrials.gov

Profile

Identifiers & mechanism

Canonical identifiers, marketed brand names and mechanism, resolved across RxNorm, ChEMBL and ATC.

Canonical name

Lasofoxifene

Aliases & brands

(-)-cis-5,6,7,8-Tetrahydro-6-phenyl-5-(p-(2-(1-pyrrolidinyl)ethoxy)phenyl)-2-naphthol

RxNorm CUI

300511

ChEMBL ID

CHEMBL328190

ATC codes

G03XC03

UNII

337G83N988

Primary mechanism

Estrogen receptor modulator

Pharmacology & targets

2 targets

Known molecular targets and mechanisms supported by curated pharmacology databases.

Estrogen receptor

ESR1 · P03372

MODULATOREstrogen receptor modulator

Estrogen receptor beta

ESR2 · Q92731

MODULATOREstrogen receptor modulator

Clinical trials

6 trials

The current development programme across all trial phases — status mix, phase distribution and the late-stage studies shaping the evidence base.

Development programme

CLINICALTRIALS.GOV · LIVE REGISTRY

registered trials across all phases

LATEST COMPLETION 2025

Active studies

Recruiting

Late-stage (III+)

Completed

PHASE DISTRIBUTIONn = 6

Phase 24Phase 32

Late-stage studies

Phase III+ trials still open or recently active — where late-stage evidence is being generated.

PEARL: Postmenopausal Evaluation And Risk-Reduction With Lasofoxifene

CompletedPH IIIKey trialLigand Pharmaceuticalsn=8,5562007

Double-Blind Placebo-Controlled Trial Of The Safety, Toleration and Efficacy Of Lasofoxifene 0.25 Mg/D and Raloxifene 60Mg/D For The Prevention Of Bone Loss In Postmenopausal Women

CompletedPH IIILigand Pharmaceuticalsn=5402005

Recent completions

Trials that read out recently, adding to the completed evidence base.

CompletedPH IISermonix Pharmaceuticals Inc.n=1002025

PEARL: Postmenopausal Evaluation And Risk-Reduction With Lasofoxifene

CompletedPH IIIKey trialLigand Pharmaceuticalsn=8,5562007

The Effect Of Lasofoxifene On Local Mediators Of Bone Resorption In The Prevention Of Postmenopausal Osteoporosis

CompletedPH IILigand Pharmaceuticalsn=512007

Dose Response Study Of Lasofoxifene In Postmenopausal Women With Osteoporosis (Placebo-Controlled, Multicenter, Double-Blind, Comparative Study) - Japanese Asian Dose Evaluation: JADE

CompletedPH IILigand Pharmaceuticalsn=4972006

Double-Blind Placebo-Controlled Trial Of The Safety, Toleration and Efficacy Of Lasofoxifene 0.25 Mg/D and Raloxifene 60Mg/D For The Prevention Of Bone Loss In Postmenopausal Women

CompletedPH IIILigand Pharmaceuticalsn=5402005

Research activity

2 papers

Key research shaping understanding of this drug, combining the latest publications with the most influential evidence.

Most influential

Annals of oncology : official journal of the European Society for Medical Oncology · 2023 · 37 cites

Lasofoxifene versus fulvestrant for ER+/HER2- metastatic breast cancer with an ESR1 mutation: results from the randomized, phase II ELAINE 1 trial.

Annals of oncology : official journal of the European Society for Medical Oncology · 2023 · 33 cites

Related diseases

1 conditions

Regulator-approved indications and conditions co-mentioned with this drug across the research literature. Number shows shared papers.

Active research areas

Breast Neoplasms2

Related drugs

2 matches

Drugs sharing diseases, protein targets and literature with this one. Ranked by graph evidence (shared targets + diseases weighted above co-mentions).

Fulvestrant

Acts on the same molecular target as Lasofoxifene, with 2 overlapping disease areas.

Shared target2 shared diseases1 shared paper

Abemaciclib

Studied across 2 of the same disease areas as Lasofoxifene in the shared literature.

2 shared diseases1 shared paper

References & data sources

RxNorm (U.S. National Library of Medicine) — drug identity
ChEMBL (EMBL-EBI) & UniProt — pharmacology and targets
Europe PMC — research literature
ClinicalTrials.gov — clinical trials